Search results
Results from the WOW.Com Content Network
A rather different view is presented in a 2013 analysis by Hao and Xue. Their preferred cladogram shows the zosterophylls and associated genera basal to both the lycopodiopsids and the euphyllophytes, so that there is no clade corresponding to the broadly defined group of lycophytes used by other authors. [19]
Lycopodiopsida is a class of vascular plants also known as lycopsids, [1] lycopods, or lycophytes. Members of the class are also called clubmosses , firmosses , spikemosses and quillworts . They have dichotomously branching stems bearing simple leaves called microphylls and reproduce by means of spores borne in sporangia on the sides of the ...
Members of the family share the common feature of having a microphyll, which is a "small leaf with a single vein, and not associated with a leaf gap in the central vascular system." [ 4 ] In Lycopodiaceae, the microphylls often densely cover the stem in a linear, scale-like, or appressed fashion to the stem, and the leaves are either opposite ...
The Human Cell Atlas project, which started in 2016, had as one of its goals to "catalog all cell types (for example, immune cells or brain cells) and sub-types in the human body". [13] By 2018, the Human Cell Atlas description based the project on the assumption that "our characterization of the hundreds of types and subtypes of cells in the ...
Plant cells differentiate into multiple cell types, forming tissues such as the vascular tissue with specialized xylem and phloem of leaf veins and stems, and organs with different physiological functions such as roots to absorb water and minerals, stems for support and to transport water and synthesized molecules, leaves for photosynthesis ...
This category is for the "lycophytes". Their formal classification varies as of July 2019 [update] ; this category is for the broadest circumscription including the extinct zosterophylls (e.g. subdivision Lycophytina of Kenrick & Crane (1997)).
The cortex of Lepidodendrids typically consisted of the inner, middle, and outer cortex, distinguished by their cell types. The inner cortex is the narrowest and consists of small parenchyma cells; secretory cells, lacunae, and various sclerotic cells also can be found in this section. The middle cortex is larger and in turn consists of larger ...
The fossil record appears to display these traits in this order, [4] but this may be a coincidence, as the record is incomplete. The telome theory proposes instead that both microphylls and megaphylls originated by the reduction; microphylls by reduction of a single telome branch, and megaphylls by evolution from branched portions of a telome.